Strap guide yoke for an automatic strapping machine

ABSTRACT

A STRAP GUIDE YOKE FORMED INTO A LOOP IS CONSTRUCTED FROM A CHANNEL MEMBER HAVING A PAIR OF LEG PORTIONS OF GENERALLY U-SHAPE CROSS SECTION. SUCH CHANNEL MEMBER IS PROVIDED OVER THE LENGTH OF EACH END FACES OF SAID LEG PORTIONS THEREOF WITH ONE OR MORE FLEXIBLE MEMBERS OF LONG AND NARROW FLAT SHAPE WHICH ARE ARRANGED IN SERIES IN A MANNER AS TO PERMIT THE SAME TO BE PARTIALLY RENEWED AT LEAST, AND SAID CHANNEL MEMBER IS FORMED INTO A UNIT BY DETACHABLY ASSEMBLING A PLURALITY OF RESPECTIVE QUADRANTS AND STRAIGHT ARMS IN A PREDETERMINED ORDER.

March 1971 YASUMORI KURIHARA 3,

STRAP GUIDE YOKE FOR AN AUTOMATIC STRAPPING MACHINE Filed Nov 13, 1968 4 Sheets-Sheet 1 NVENTOR YASUMORI KURIHARA ATTORNEYS March 23, 1971 YASUMORI KURIHARA I STRAP GUIDE YOKE FOR AN AUTOMATIC STRAPPING MACHINE Filed NOV. 13, 1968 I6 is rIYS- l 4 Sheets-Sheet 2 FIG.5

6 r E: i- A 4 r/ I/ l/I/l/l/ll/A k; 5 $5M 6 FIG-6 INVENTOR YASUMORI KURIHARA ATTORNEYS MflrCh 1971 YASUMORI KURIHARA 3,572,237

STRAP GUIDE YOKE FOR AN AUTOMATIC STRA'PPING MACHINE Filed Nov. 13, 1968 4 Sheets-Sheet a INVENTOR FIGJO YASUMORI KUR'HARA BY /wM ATTORNEYS March 23, l97l YASUMORI KURIHARA 3,572,237

1 STRAP GUIDE YOKE FOR AN AUTOMATIC STRAPPING MACHINE Filed Nov. 1.3. 1968 4Sheets-Sheet 4 INVENTOR YASUMQRI KURIHARA BY WWW/i, @a/ZM ATTORNEYS United States Patent 6 US. Cl. 100-26 4 Claims ABSTRACT 1115 THE DISCLOSURE A strap guide yoke formed into a loop is constructed from a channel member having a pair of leg portions of generally U-shape cross section. Such channel member is provided over the length of each end faces of said leg portions thereof with one or more flexible members of long and narrow fiat shape which are arranged in series in a manner as to permit the same to be partially renewed at least, and said channel member is formed into a unit by detachably assembling a plurality of respective quadrants and straight arms in a predetermined order.

This invention relates to a machine for strapping bundless, boxes, packages and the like and more particularly to a strap guide yoke therefor which can be adapted for guiding steel strapping and thermoplastic strapping made of nylon, polypropylene or the like.

It is well-known that in some systems for strapping an article or package to be tied, a strap guide yoke is employed which is arranged to encircle the package to assist the strap from being guided into a loop form, and that said strap guide yoke is provided by bending a suitable length of a metallic member of channel-section or I-section into a proper shape such as substantially a rectangle which conforms to contour of the package to be tied, and the same has a flexible member of C-shaped cross section (mold goods of such as a rubber or the like) fitted into the channel thereof in a relationship, wherein each open side thereof face toward the same direction.

The use of the flexible member of the abovementioned type would make it necessary to manufacture a rubber or the like into the form of C-shaped cross section, with the inconvenience that the manufacture of flexible member would be expensive. Also, since said flexible member is obliged to be of jointless construction because of the same being mounted in the channel, in the event of the same being damaged it would become necessary to replace the used rubber as a Whole by a new, even partial damage. It will be further pointed out that sliding movement of the strap with respect to the inner contacting surface of the flexible member of the aforementioned type creates a large friction so that it is required to devise a proper measure. For this purpose, said inner surface is preferably provided with a strip of suitable metallic material to decrease a sliding friction to be caused by the strap movement. Furthermore, since the strap guide yoke is constructed from only one channel member as previously described, this would make it necessary to manufacture as many different strap guide yokes as are the package types to be tied, with the inconvenience that this would become cumbersome, expensive and unpractical.

It accordingly is the principal object of the invention to obviate such inconveniences by means of improvements in a strap guide yoke.

Other objects and advantages of the invention will be readily apparent from the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals indicate like parts throughout the figures:

FIG. 1 is a fragmental schematic side elevational view of a strapping machine equipped with a strap guide yoke according to the present invention;

FIG. 2 is a fragmental detail view illustrating the lefthand lower portion of the strap guide yoke in fixed en gagement with the base section of the strapping machine;

FIG. 3 is a view corresponding to that of FIG. 2, but illustrating the righthand lower portion;

FIG, 4 is a sectional view taken on line IV-IV of FIG. 2;

FIGS. 5 and 6 are sectional views taken on lines VV and VI-VI, respectively, of FIG. 3;

FIG. 7 is a perspective view explaining a method of manufacture of quadrants each forming a part of the strap guide yoke;

FIG. 8 is an enlarged perspective View taken on line VIIIVIII of FIG. 1, with the strap received therein;

FIG. 9 is a fragmental cross-sectional enlarged view illustrating the detailed construction of the yoke;

FIG. 10 is a fragmental sectional view illustrating the strap being shrunk into article binding engagement;

FIG. 11A is a skeleton, on a decreased scale, of the yoke shown in FIG. 1; and

FIGS. 11B to 11D are skeletons of strap guide yokes constructed in accordance with the present invention.

Referring now to the drawings, and initially to FIG. 1, there is partly shown an automatic strapping machine designated by the reference numeral 1 and equipped with a strap guide yoke 2 according to this invention. The strap guide yoke 2 is adapted to loosely encircle an article or package to be tied (not shown) and therefore formed, for example, into substantially a rectangular shape similar to the contour of the package to be tied. The strap guide yoke 2 is fixedly mounted at the bottom portions thereof on a bracket arm 3 and a guide block member 4- in a usual manner as will be shown in FIGS. 1 to 6. Said bracket arm 3 and the guide block 4, in turn, are securely attached to the base section of the strapping machine 1, as by bolts (not shown). The strapping machine 1 includes a pair of rolls 5, 5 which are operable to draw strap from a supply (not shown) and push feed the strap along the strap guide yoke 2 and around the package to be tied to form a loose loop configuration, a table 6 on which the package to be tied is disposed, a grooved retractable member '7 serving to lead a length of strap from said guide block member 4 to the strap guide yoke 2 during feeding of the strap, a strap pusher 8 with a cutter chip 32 and a saw-tooth top surface, a press jaw 9, and a second press jaw 10 with a cutter 33.

As thus far described, the arrangement is substantially conventional.

'Referring to FIGS. 8 and 9, the strap guide yoke 2 is constructed from an elongated channel-shaped member 11 with a channel 12 through which a strap 13 travels during feeding thereof. On each of end faces 14 and 15 of spaced legs of U of the channel member 11, there is mounted a flexible belt member or members 16 in parallelism relationship with each other to prevent disengagement of the strap 13 from the channel 12. As all belt mernbers 16 are just the same excepting the length thereof, only one lefthand belt 16 will be described hereinafter. It will be understood that, of course, said belt member (or members) 16 is provided over the length of the strap guide yoke 2 and has a width sufficient to prevent disengagement of the strap 13 from the groove 12. Therefore, the belt 16 is at least wider than the end face 14, so that the open side of the channel 12 will be partially covered with the projecting ends of the lefthand and righthand belts 16, 16. As thus formed, there is no fear of disengagement of the strap 13 from the channel 12 during its travel therealong. Said belt member 16 may be attached to the wall 14 of the channel member 11 by means of such as 3 a plurality of butterfly nuts 17 (only one shown, as illustrated in FIG. 9), a plurality of round headscrews 18 (FIGS. 2 to 6), or the like. Preferably, the belt member 16 is fastened through a member 19 having a width substantially equal to that of the wall 14.

According to this invention, as previously described, the flexible member 16 is in the long and narrow fiat shape so that flat belts on the market may preferably be employed as flexible members resulting in decrease in manufacturing costs of the flexible member. Such flat belts are made of a number of different mateirals, including leather, fabric, rubber-impregnated fabric, and combinations of leather and synthetics. It will be easily understood that any damaged portion of the flexible member 16 may be cut away and replaced by a suitable length of new belt with no fear in feeding operation that the tip of the strap is caught in junctions in contradiction to the conventional yoke, because the belt 16 is not mounted in the channel 12. It will be further recognized from FIGS. 2 and 3 that preferably, two successive flexible members may be slightly lapped at 29 to prevent misfeed of the strap or entanglement of the strap.

In one embodiment as best shown in FIG. 1, the com pleted strap guide yoke 2 formed of the aforementioned channel member 11 comprises four quadrants A, B, C and D each forming one of the four corner portions of the yoke 2, and five straight arms, that i the horizontal top E, the two vertical sides F and I, and the two horizontal bottoms G and H. The series of quadrants and straight arms are fixedly connected alternately with each other, as by bolts 21 shown in FIGS. 2 and 3. As will be seen from FIG. 2, an end portion designated by 22 of the straight arm H is formed into a stepped shape by machining or otherwise to be snugly engaged with the next quadrant C by means of the bolts 21 so that in operation the strap will be smoothly guided along the contour formed by the yoke. If desired, any straight arm and an adjacent quadrant (or other straight arm as shown in FIG. 11D) may be butt-joined by attaching a doubling plate over them. In this case, the straight arms have no need of any stepped end portions.

As previously described, in FIGS. 1 to 6, the lefthand bottom straight arm H is rigidly secured to the bracket arm 3 by means of a plurality of spaced bolts 23, and the righthand bottom straight arm G is also rigidly secured to the guide block member 4 by means of bolts 24. The guide block 4 i composed of a member 25 and a member 26 with a groove 27 for guiding the strap, and the same is connected to a bracket 28 (FIG. 1), as by bolts (not shown), mounted on the base section of the machine 1 within which various mechanism are contained. It will be easily understood that the strap guide yoke 2 extends upwardly from the base section of the machine in a manner allowing the lefthand bottom H to be arranged in alignment with said guide block 4 and the righthand bot tom G to be arranged in parallelism superposed relationship with the guide block 4 for the purpose hereinafter mentioned.

The strap guide yoke 2 is thus formed into a unit by assembling the quadrants and the straight arms of the above type, so that it will be easily understood that the yoke 2 can be made in various sizes merely by changing its vertical arms and/or horizontal arms with longer or shorter ones constituting modular arm sections. In FIG. 11B, longer straight side arms I and F are used respectively instead of the aforementioned straight arms I and F of FIGS. 1 and 11A. In FIG. 11C, longer horizontal top E and bottom H' is employed, and in embodiments in FIG. 11D, a plurality of standardized straight arms E, F" and I" respectively are used and arranged in a row in the hereinbefore mentioned manner. Thus, it will be apparent that due to the standardization of straight arms, various sizes of yokes such as shown by the dotted line and the dot-dash line can be provided with ease and at will.

Referring to FIG. 7, there are shown the quadrants A, B, C and D arranged in a substantially annular form in explanation of a method of manufacture thereof. It will easily be imagined that these quadrants are formed of a torus of suitable dimentions in a manner, wherein the torus is divided into four substantially equal parts, and later the resulting quadrants are accurately machined into a shape of channel cross section. With respect to the straight arms E, F, etc., these are formed of a square bar cut to a predetermined standard length and therefore can be manufactured with ease and accuracy by the use of a suitable machine tool such as a lathe, a shaper, etc.

The arrangement thus far described is operated as follows:

It will be understood from FIG. 1 that, upon the forward rotation of the feed rolls 5, 5 (in the direction of the solid arrow), the strap 13 is drawn from the supply (not shown) and push fed through the groove 27 of the guide block member 4, a bore 29 of the strap pusher 8 and a groove 30 formed in the pilot member 7 to enter the channel 12 of the horizontal bottom arm H, the strap following a travel path which leads through the lefthand lower quadrant C, then upwardly itno the horizontal top arm E to cross the top of the package to be tied, then down the righthand side arm F, then across the bottom of the package and terminates at a position designated by 31 on the pilot member 7 to present overlapping strap ends for scaling in any conventional manner. With the strap thus formed into a loop extending across the table 6 and through the yoke 2, the machine is conditioned for performing the strapping operation. As will be seen from FIG. 10, shortly after the tip or free end of the strap 13 reached the position 31, the strap pusher 8 ascends to the table 6 to firmly hold the strap 13 between the table 6 and the pusher 8 and then the pilot member 7 is retracted (in FIG. 10, the pilot member 7 is in retracted position) to a certain extent, sufficient to effect the sealing operation without any hindrance, in a direction in which the same is disengageable from the strap (the retraction of the pilot member may be effected by means of e.g. a cam and link mechanism). Under these circumstances, upon the backward rotation of the feed rolls (in the direction of the dotted arrow in FIG. 1), the tension is applied on the strap whereupon the latter is drawn down against the package and can escape from the channel 12 of the yoke 2. Consequently, the strap loop is shrunk into binding engagement with the package to be tied. After this tensioning or tightening operation, said overlapping ends of the strap are secured to each other by means of a conventional heat seal (not shown) and later the strap is cut by the ascending cutter chip 32 and cutter 33 as the jaw 10 continues to ascend in a conventional and well-known manner.

While the invention has been illustrated and described with reference to preferred embodiments thereof, it is to be understood that various changes in the details of constructions and the arrangement and combination of parts may be resorted to without departing from the spirit and scope of the invention.

What I claim is:

1. In a strap guide yoke for an automatic strapping machine provided on its base section with a strap jointing and cutting unit, a bracket arm, a channeled guide block for guiding a length of strap to said guide yoke, and a table for supporting an article to be strap tied, the combination of:

(1) a channel member formed substantially into a rectangle with a gap bridged by said strap jointing and cutting unit and vertically disposed on said bracket arm and guide block, said channel member including a pair of spaced apart leg portions projecting inwardly of the rectangle and further comprising:

(a) four quadrantal corner parts, constituting a lower left quadrant, an upper left quadrant, an upper right quadrant and a lower right quadrant;

(b) a first horizontal bottom straight arm detachably connected to said bracket arm and said lower left quadrant so as to be in alignment with said guide block;

(c) a second horizontal bottom straight arm detachably connected to said guide block and said lower right quardant;

(d) a vertical leftside straight arm detachably connected in series between said left upper and lower quadrants;

(e) a vertical rightside straight arm detachably connected in series between said right upper and lower quadrants;

(f) a horizontal top straight arm detachably connected in series between said left and right upper quadrants; and

(2) a pair of flexible members detachably mounted on a pair of end faces of said leg portions to help retain the tie-strap during a strapping operation.

2. The combination as defined in claim 1, wherein each of said straight arms is selectively and detachably connectable in series with at least one other standardized separate straight arm, whereby said guide yoke is selectively changeable in its length and height to correspond to the size need of the article to be tied.

3. The combination as defined in claim 2 wherein said other standardized separate straight arms include a plurality of equal length arms to constitute modular interchangeable arm sections.

4. In a strap guide yoke for an automatic strapping machine provided on its base section with a strap jointing and cutting unit, a bracket arm, a channeled guide block for guiding a length of strap to said guide yoke, and a table for supporting an article to be strap tied, the combination of:

(l) a channel member formed substantially into a rectangle with a gap bridged by said strap jointing and cutting unit and vertically disposed on said bracket arm and guide block, said channel member including a pair of spaced apart leg portions projecting inwardly of the rectangle and further comprising:

(a) four quadrantal corner parts, constituting a lower left quadrant, an upper left quadrant, an upper right quadrant and a lower right quadrant;

(b) a first horizontal bottom straight arm detachably connected to said bracket arm and said lower left quadrant so as to be in alignment with said guide block;

(c) a second horizontal bottom straight arm detachably connected to said guide block and said lower right quadrant;

(d) a vertical leftside straight arm detachably connected in series between said left upper and lower quadrants;

(e) a vertical rightside straight arm detachably connected in series between said right upper and lower quadrants;

(f) a horizontal top straight arm detachably connected in series between said left and right upper quadrants; and

(g) each of said straight arms being selectively and detachably connectable in series with at least one other standardized separate straight arm of equal length,

(2) said guide yoke is selectively changeable in its length and height to correspond to the size need of the article to be tied; and

(3) a pair of flexible members detachably mounted on a pair of end faces of said leg portions to help retain the tie-strap during a strapping operation.

References Cited UNITED STATES PATENTS 1,937,675 12/1933 Twomley 100-26UX 2,114,150 4/1938 Rodman 29-428X 2,780,986 2/1957 Ritenour 100-25 2,853,938 9/1958 Hall et a1. 100-26 3,031,949 5/1962 Daniels ct a1. 100-26 3,070,001 12/1962 Feldkamp 100-25 3,093,063 6/1963 Van Der Wal 100-26 FOREIGN PATENTS 1,317,243 1/1963 France 100-26 837,762 6/ 1960 Great Britain 100-26 BILLY J. WILHITE, Primary Examiner US. Cl. X.R. 29-428 

